[Oystein]

I know there is some sceptism about the effect of special audio grade fuses ( ceramic and gold plated, etc .. )
I believe that there is some psychological effect that "proves" that there is indeed an increase in SQ.
There will be some situations where it will improve but this is a matter of synergy with the rest of the electronics.
Maybe if you take out the old fuses, clean them with alcohol (incl. holder !!) the effect will be the same because the cleaning does the job ... not the fuse ...
Has anyone tried/replaced the fuses in the Odyssey amps for audio grade models and what did you observe ?

Oystein

[Oystein]

In the meantime I realised to use the "search" option heren on AudioCircle.
I see there were already some discussions active early 2008 so my question is not a new subject here. I will get some audio grade fuses (also for my pre-amp) and see what will happen 

[dhrab]

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[Wolfman]

Guys,
Don't replace the internal fuses with slo blows,there's a good reason Klaus went to internal fast blows.
I would call Klaus first but he didn't change the original Symphonic Line slow blows to fast blows on a whim. These power supplies are nicely engineered,but can be touchy to outside power irregularities/stupid owner mistakes.
Don't ask me how I know........         

The Littlefuse ceramic idea is a good one. Klaus replaced my internal glass fuses to ceramic ones(not sure if Littles,but similiar) when he did the "G.C." upgrade and they're almost as good as the pricy ones. My Xindac Silver fuses are still a mite better,but not enough that I would pay $200 or more for 8 internals now.

Check with the Man,maybe he can sell you what he's putting in now,or steer you to a cheap place to buy.

The two external fuses are still slo blows,however.

Good luck.

[markC]

Very good advice. NEVER replace a specified fast blow with a slow blow. It's fast blow for a reason!

[Oystein]

I know not to replace the fast blow for slow.
I suppose these 4 fast blow fuses are in the + and - rails that feed the output transistors.
If one of the transistors would short-circuit you bet you will damage more parts or maybe even some traces on the PCB using slow blow.
Semiconductors like tansistors are like fast blow when overloaded themselves. They tend to short themselves when defect which in turn will blow the fuses beacuse of the high (short-circuit) current.
The sooner you can limit/protect such a failure the better.

[Wolfman]

Oystein,
Sounds like you know your way around amp internals much better than me,I just had to error on the side of cautious.

I've never heard the HiFi or Furutech fuses,I'm sure they're probably better than my Xindacs as they're still glass and  I'd be willing to bet a large part of the better sound is that ceramic case/filling plus Silver and or Gold wire/plating,etc.

If you want the last 0.5%(or less) improvement,and are willing to spend the bucks,the pricey fuses will give you that. I'm just not sure at this point with how good the cheaper ceramic fuses are that the amount of money charged wouldn't be better spent elsewhere.

As always,YMMV,system synergy,priorities,etc.

If you do go with them,let us know what you think.
I'd definitely be interested in your impressions.
Good luck.       

[Oystein]

I was also considering using common ceramic fuses from Siba or Bussmann.
They use probably copper wire inside the fuse but I would not be surprised if they use silver.
I know they use silver in the high-current fuses as are used in the mains distribution that go up to 600A.
You buy the 5x20 mm ceramic fuses for a few Euro's (10 pack !!) so this is a real bargain compared to the HiFi Tuning models with gold plated caps. So hardly any money wasted for a test 
As a total package I am wondering how much improvement the gold-plated fuses will have knowing that the fuseholder is probably nickel plated stamped steel and the PCB traces are made of copper.
Clean both the fuse and fuseholder with alcohol or any other "conductive improving" celaner and I think you can reach almost the same level of "performance" as the real expensive fuses.

I am still breaking in my amp but when it is settled I will start tweaking and the fuses will be a part of it. But I will post my observations when I get to it.

[Oystein]

As promised above I would tell my experiences replacing the installed glass fuses by ceramic fuses. Nothing fancy or gold-plated but the common Siba 5x20 mm ceramics.

The short story: I do not know the exact upgrade potential for the fuses alone ...

I bought the amp new in September and by now it has been burnt-in completely. I left the power on since then and having music playing for a few hours a day.
One of the other plans I had is to set the bias-current and off-set voltage after break-in as the electronics has stabilised by now.
I got the adjustement specs from Klaus and I have the equipment (oscilloscope and digital multi-meter) to perform such a job.

The values were a little off the mark so I re-adjusted everything and replaced the fuses too.
I measured the correct phase of the line-voltage which gave little clues which position would be optimal but having the lid open I could see the wires from the internal transformer connected to the switch and power entry.
I connected the mains plug according to the colour-codes of the wires inside but this was actually reversed from how it was connected the last months.

The only thing I can tell you is that the sounds make a big leap forward - much more and detailed bottom end - I was surprised my speakers could do this - and higher resolution of individual instruments.

All the efforts were really worthwhile but if you ask me what improvements were caused by the fuses alone ? I have no f*ck*ng idea 

I did not feel like doing the adjustments and fuse replacement in separate sessions but I am a happy guy anyway.

[Wolfman]

Oystein-thanks for getting back to us.Trying to tell differences between fuses on Odyssey amps is tough because you have to totally shut them down and let the caps drain if you want to be safe.

It takes awhile for them to stabilise on restart so you're trying to tell small differences using memory,not good. Mine take upwards of 12-24 hours to fully come back judging by ear.

You could just run them the way they are for a length of time and get good and used to the sound and then switch the old fuses in and see if anything leaps out. Frankly it's  usually more trouble than it's worth,but what the heck,something to do on some snowy/rainly day